通话中参数不足

Question

I'm trying to create a go app that will display the users IP.

I can't figure out my Log Console error:

go:14: not enough arguments in call to getJsonRes

Go app code:

package main

import (
    "encoding/json"
    "net/http"
    "fmt"
)

type Addrs struct {
    ip string
}

func handler(w http.ResponseWriter, r *http.Request) {
    response, err := getJsonRes()
    if err != nil {
    http.Error(w, err.Error(), http.StatusInternalServerError)
    return
    }
    w.Header().Set("Content-Type", "application/json")
    fmt.Fprintf(w, string(response))
}

func main() {
    http.HandleFunc("/", handler)
}

func getJsonRes(r *http.Request)([]byte, error ) {
    ip := Addrs{ r.RemoteAddr }

    return json.MarshalIndent(ip, "", " ")
}

Answer 1

Your function

func getJsonRes(r *http.Request)([]byte, error )

Takes a request pointer and returns a byte array and or an error.

On this line

response, err := getJsonRes()

You call it with with no arguments. You probably meant to do the following

response, err := getJsonRes(r)